Earth boring apparatus

ABSTRACT

An earth boring apparatus including at least two kelly members telescoping into and rotatable within an outer barrel. And fluid means adapted to extend and retract said kelly members. One of said kelly members comprises an outer member of square crosssection and an inner circular member secured therein. The exterior of the inner member is in contacting engagement with the interior of the outer member along the length of both members and angular fluid passageways are provided therebetween.

States Patent 11 1 1451 Jan. 28, 1975 3,768,578 10/1973 Russell ..173 150 Primary Examiner-Ernest R. Purser Attorney, Agent, or Firm-C. M. Kucera [57] ABSTRACT An earth boring apparatus including at least two kelly members telescoping into and rotatable within an outer barrel. And fluid means adapted to extend and retract said kelly members. One of said kelly members comprises an outer member of square cross-section and an inner circular member secured therein. The exterior of the inner member is in contacting engagement with the interior of the outer member along the length of both members and angular fluid passageways are provided therebetween.

5 Claims, 6 Drawing Figures PATEHTEB JAN 2 8 I975 SHEET 2 BF 2 1 EARTH BORING APPARATUS FIELD OF THE INVENTION The present invention relates to rotary earth boring rigs and in particular to a telescoping mast and kelly assembly therefor, and is here described as it applies to relatively light weight, truck-transportable rigs for drilling relatively shallow holes for foundations, post holes, telephone post holes, wells, and the like. Such holes may range from a few inches to six feet or larger in diameter. Drilling rigs of this type may penetrate earth formations by rotating an auger or other type of bit, which is attached to the lower end of a drill stem or kelly, while applying an axial load to the kelly and bit.

PRIOR ART Portable drilling rigs are extensively used wherein a winch or fluid is utilized to raise and lower a kelly which also is driven to provide rotation to an auger on the lower end thereof. As deeper holes are required, longer cylinders and kellys are utilized, with the result that on some units the long kelly tends to buckle or whip in operation. This action may damage the kelly or the interior surfaces of the cylinders. Also, simply to make the kelly longer may result in an apparatus which is cumbersome, expensive to make and maintain and one which may require special permits each time the apparatus is moved over public roads.

SUMMARY In accordance with the present invention, a telescoping kelly assembly is provided which is not extensive in height, requires smaller parts and support vehicles, is simpler to make and maintain, and wherein the extension and retraction of the kellys is effected with a central fluid control valve. Special moving permits may not be needed for this apparatus since it can be smaller in height and length than prior machines of the same capacity. BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a somewhat simplified, fragmentary side elevation view showing the drilling rig raised to its operative position at the rear end of a truck or the like.

FIG. 2 is a perspective sectional view of the drilling rig mast assembly showing the telescoping kelly members.

FIG. 3 is a sectional view taken along line 3-3 inFIG. 2.

FIG. 4 is a sectional view taken along line 4-4 in FIG. 2.

FIG. 5 is a schematic of the hydraulic circuit with the control valve positioned to extend the kelly members.

FIG. 6 is a schematic of the hydraulic circuit with the valve positioned to retract the kelly members.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drilling rig 10 is illustrated in FIG. 1 comprising a mast assembly 11 mounted upon a truck 12 or other transporter. The truck carries the engine prime mover, fuel, hydraulic tanks, drive train, pumps and other aux iliary equipment required to operate the drilling rig to rotate and lower a drill bit 5 into the earth, as is well known in the art.

Referring to FIG. 2, the mast assembly 11 comprises an outer barrel or cylinder 13, an intermediate kelly member 14 which includes a member 15 which is noncircular in cross-section and an inner cylindrical member 16 which is within, fastened to and substantially coextensive with the member I5. An inner kelly member 17 has a non-circular cross-section and is disposed within the inner cylindrical member 16.

The intermediate member 14 may have a piston 18 mounted on the upper end thereof and adapted for rotation and sliding and sealing engagement with the inside surface of the outer cylinder'barrel 13. The inner kelly member 17 also may have a piston 19 on the upper end thereof and adapted for non-rotational sliding and sealing engagement with respect to the inside surface of the inner cylindrical member I6.

The member 15 which is non-circular in cross section is axially slidable through a kelly driver 20 which has an opening therethrough conforming to the non-circular shape of the member 15 so that the member 15, carrying with it member 16 may be rotated by the kelly driver 20 by means of geartrain 21a.

The intermediate member 14 has a drive bushing 21 on the lower end thereof. The inner kelly 17 which is non-circular in cross-section is axially slidable through drive bushing 21 which has an opening therethrough conforming to the non-circular shape of the inner kelly member 17 so that the kelly 17 may be rotated by the drive bushing 21 which is attached to and rotates and moves with the intermediate kelly member 14.

A seal 30 is provided at the lowerportion of the outerbarrel 13 for a sliding seal with the non-circular member 15 and to provide for a rotary seal with the nonrotating barrel 13. A similar type seal 31 is provided in the drive bushing 21, though for a sliding seal only with the non-circular and rotatable inner kelly 17.

Thus it can be seen that intermediate member 14 may rotate relative to and move axially with respect to the outer barrel 13.

The inner kelly member 17 may move axially with respect to the intermediate memberl4 but must rotate therewith. Both members 14 and 17 may move axially upwardly until they are telescoped substantially coextensively with the outer barrel 13, to provide a compact and relatively short mast assembly for a drilling rig.

The members 15 and 17 are described as being noncircular in cross-section and are here shown as being square in cross-section. It will be apparent that other shapes and arrangements may be employed to provide driving connections'to the kelly members.

Referring particularly to FIG. 5, the operation of the earth boring apparatus to extend the kellys is as follows: fluid is pumped through passageway 40 into the outer barrel l3 and such pressure fluid exerts a downward force upon the tops of pistons 18 and 19 while the kelly members 14 and 17 are rotated to drive the bit 5 into the earth formation being encountered. As drilling progresses, the kelly members 14 and 17 are extended until the piston 18 engages stop 41 and piston 19 engages stop 42. As the kellys are thus being hydraulically extended, the fluid present in the mast assembly returns to s fluid reservoir 48 through passageways 43 into passageway 44, which is the space between the square kelly 15 and the cylinder 16, through passageways 45 into the space 46 between the square kelly 15 and the inner surface of the outer barrel 13, through passageway 47 into the reservoir 48.

To retract the kellys, the valve is turned to the position shown in FIG. 6, and fluid is pumped through passageways 47 and 46 and exerts an upward force on the underside of piston 18, through passageways 45 and 43 and space 43a to exert an upward force on the underside of piston 19, thus retracting both kelly members 14 and 17 substantially into the outer barrel 13. As the kellys are retracted, the hydraulic fluid in the mast exhausts through passageway 40 to return to the reservoir 48.

The invention thus provides a positive hydraulic control for extension and retraction of the kelly members and one in which the kelly members are lubricated by the hydraulic fluid to alleviate sticking and wear thereof. The arrangement of the invention also provides a relatively compact earth boring apparatus for a given capacity.

While two kelly members are here shown, it will be apparent that more can be provided, in accordance with the teachings hereof, if desired.

In providing an outer barrel enclosing a kelly member having a non-circular cross-section outer member and a cylindrical member disposed within and attached to the kelly and movable therewith, I am able to use the spaces between such members, as well as the space between cylinder 16 and kelly 17, as integral fluid conduits thus reducing the requirements for separate, exterior fluid conduits. Such present arrangement also allows the kelly member 14 to be rotatable within and in sealing and sliding engagement with the outer barrel 13 of the mast assembly 11, resulting in a boring apparatus which is relatively simple in design, economical to manufacture and easy to operate and maintain.

I The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is:

1. In a rotary drilling rig of the type having a kelly driver for rotating an axially advancing drill bit. a mast assembly comprising:

an outer non-rotatable barrel defining an elongated internal cylinder;

an intermediate elongated member slidable and rotatable within said outer barrel and comprising an outer kelly member having a non-circular crosssection adapted to be rotatably driven by the drilling rig, an inner cylindrical member secured within and rotatable with said outer kelly member. and means sealing adjacent ends of said outer kelly member and said inner cylindrical member, the exterior of the inner cylindrical member contacting the interior of the non-circular outer kelly member along the length thereof and defining elongated fluid passageways of angular section along the length of said intermediate member;

an inner kelly member slidable within said inner cylindrical member and adapted to be rotatably driven by said intermediate member; and

fluid means including said passageways adapted to extend said intermediate member out of said outer barrel and said innerkelly out of said intermediate member, and to retract said intermediate member into said outer barrel and said inner kelly into said intermediate member.

2. A rotary drilling rig according to claim 1 including:

a drill bit on the lower portion of said inner kelly.

3. A rotary drilling rig according to claim 2 wherein said drill bit is an earth auger.

4. A rotary drilling rig according to claim 1 wherein the said intermediate member includes a piston in sliding and sealing engagement with the said outer barrel.

5. A rotary drilling rig according to claim 1 wherein the said inner kelly member includes a piston in sliding and sealing engagement with the said inner member. 

1. In a rotary drilling rig of the type having a kelly driver for rotating an axially advancing drill bit, a mast assembly comprising: an outer non-rotatable barrel defining an elongated internal cylinder; an intermediate elongated member slidable and rotatable within said outer barrel and comprising an outer kelly member having a non-circular cross-section adapted to be rotatably driven by the drilling rig, an inner cylindrical member secured within and rotatable with said outer kelly member, and means sealing adjacent ends of said outer kelly member and said inner cylindrical member, the exterior of the inner cylindrical member contacting the interior of the non-circular outer kelly member along the length thereof and defining elongated fluid passageways of angular section along the length of said intermediate member; an inner kelly member slidable within said inner cylindrical member and adapted to be rotatably driven by said intermediate member; and fluid means including said passageways adapted to extend said intermediate member out of said outer barrel and said inner kelly out of said intermediate member, and to retract said intermediate member into said outer barrel and said inner kelly into said intermediate member.
 2. A rotary drilling rig according to claim 1 including: a drill bit on the lower portion of said inner kelly.
 3. A rotary drilling rig according to claim 2 wherein said drill bit is an earth auger.
 4. A rotary drilling rig according to claim 1 wherein the said intermediate member includes a piston in sliding and sealing engagement with the said outer barrel.
 5. A rotary drilling rig according to claim 1 wherein the said inner kelly member includes a piston in sliding and sealing engagement with the said inner member. 